Engineering Commons^™

Reduction Of Copper And Iron Oxide Mixture With Local Reducing Gases, Shokhrukh Khojiev

Acta of Turin Polytechnic University in Tashkent

The article analyzes the scientific problems of the copper industry. In particular, the main problem with the classical production of copper is the causes of large amounts of slag and the negative impact of these wastes on the environment. Accordingly, the main component that forms the slag is iron, and the higher its content in the original copper concentrate, the more slag is formed, and at the same time a large amount of copper metal is released into the waste. The departure is indicated by evidence. To prevent this problem, a technology has been proposed to reduce copper sulfide concentrates …

A Computational Investigation Of The Interstitial Oxidation Thermodynamics Of A Mo-Nb-Ta-W High Entropy Alloy Beyond The Dilute Regime, Adib J. Samin

Faculty Publications

High entropy alloys (HEAs) are promising candidates for high-temperature structural material applications. Oxidation is a major factor that must be accounted for when designing such materials and it is thus important to study the oxidation behavior of HEAs to enable the optimum design of next generation materials. In this study, the thermodynamic behavior of interstitial oxygen in a Mo-Nb-Ta-W high entropy alloy was explored beyond the dilute limit. This was accomplished by sampling configurations of the HEA and HEA-oxygen systems from an isothermal–isobaric ensemble using a series of first-principle-based Monte Carlo simulations. It was found that the interstitial oxygen had …

Local Structure And Dynamic Studies Of Mixed Ch4-Co2 Gas Hydrates Via Computational Simulation And Neutron Scattering, Bernadette Rita Cladek

Doctoral Dissertations

Permeated throughout the ocean floor and arctic permafrost, natural gas hydrates contain an estimated 3000 trillion cubic meters, over three times that of traditional shale deposits, of CH₄ that is accessible for extraction. Gas hydrates are a crystal structure in which water molecules form a cage network, the host, through hydrogen bonds while trapping a guest molecule such as CH₄ in the cavities. These compounds form naturally where the appropriate low temperature and high pressure conditions occur. A promising and tested method of methane recovery is through exchange with CO₂, which energetically takes place of the …

The Varied Thermal Response Of Magnetic Iron-Oxide Nanoparticles During Induction Heating In Liquid And Solid-Liquid Phase Change Mediums, Joshua Tompkins

Graduate Theses and Dissertations

This study investigates the induction heating response of uncapped iron oxide nanoparticles sonically dispersed as a nanofluid and mechanically distributed in solid phase change materials. The nanoparticles examined have a mean diameter of 14.42 nm and are magnetically heated in an alternating magnetic field at an amplitude of 72.6 kA/m at frequencies of 217, 303, and 397 kHz. Nanoparticle characterization was undertaken through transition electron microscopy, x-ray diffraction, and dynamic light scattering when in suspension. Carrier fluids were characterized through viscosity, heat capacity, and density measurements which were used in the calorimetric calculation of the specific absorption rate (SAR) of …

Parametric Study Of Residual Stresses In Wire And Arc Additive Manufactured Parts, Hisham Khaled Jamil Abusalma

Mechanical & Aerospace Engineering Theses & Dissertations

Wire and Arc Additive Manufacturing (WAAM) is a cost-effective additive manufacturing process due to its capability to fabricate large metal parts with high deposition rate and low equipment cost. Although this method is gaining popularity in manufacturing industry, more research is needed to understand process parameters’ effects on residual stress (RS) distribution and part distortion. As such, a 3D thermo-elastic-plastic transient model was established in ABAQUS and employed to investigate the effect of process parameters such as the torch speed, the deposition power and the interlayer dwell time on RS distribution and distortion in WAAM part. The numerical model utilized …

A Parametric Analysis Of A Turbofan Engine With An Auxiliary Bypass Combustion Chamber – The Turboaux Engine, Kaleab Fetahi

Mechanical & Aerospace Engineering Theses & Dissertations

A parametric study of a novel turbofan engine with an auxiliary combustion chamber, nicknamed the TurboAux engine is presented. The TurboAux engine is conceived as an extension of a low-bypass turbofan engine with an auxiliary bypass annular combustion chamber around the core stream. The study presented in this thesis is motivated by the need to facilitate clean secondary burning of fuel at temperatures higher than conventionally realized, from air exiting the low-pressure compressor. The parametric study starts by analyzing the turbojet engine and its performance with and without an afterburner segment attached. Following that, the conventional turbofan and its mixing …

Multiphase Equilibrium In A Novel Batch Dynamic Vl-Cell Unit With High Mixing: Apparatus Design And Process Simulation, Jeonghoon Kong

Electronic Thesis and Dissertation Repository

The availability of vapor pressure data is essential to validate thermodynamic models and enhance the thermodynamic correlations. Despite its importance, there is limited vapor pressure data of the multicomponent mixtures in open literature. This is the case for hydrocarbon/water blends as they are found in the naphtha recovery unit in the oil sand process.

This thesis uses a CREC-VL-Cell, a batch apparatus to measure the vapor pressures of n-octane/water, synthetic naphtha (SN)/water and solids/n-octane/water. The CREC-VL-Cell operates at thermal equilibrium with less than 1.6 % error using a 1080 rpm impeller speed and various optimized operational factors. This apparatus saves …

Thermal Control Development Of A Proton Exchange Membrane Fuel Cell System, Ola Mohammed Taha Al-Shalash

Mechanical Engineering Theses

A fuel cell is an electrochemical energy conversion device that uses fuel to generate electricity. It basically converts the chemical energy of reactants directly into electricity without combustion. In a Proton Exchange Membrane Fuel Cell (PEMFC), the reactants, hydrogen and oxygen, are fed into the two electrodes, anode and cathode, respectively. A reaction takes place at each electrode and produces electricity, as well as water, and heat as the by-products. In order to maximize performance of a fuel cell, many factors can be considered for tuning and control. Temperature management is one of these factors.

A thermal-fluid model of a …

Sequence Control Of Complex Coacervation, Li-Wei Chang

Doctoral Dissertations

Complex coacervation is a liquid-liquid phase separation driven by the complexation of oppositely charged polyelectrolytes. The resulting coacervate phase has been used for many applications, such as underwater adhesives, drug delivery, food and personal care products. There also has been increasing interest in coacervate-like droplets occurring in biological systems. The majority of these “membraneless organelles” involve a combination of intrinsically-disordered proteins and RNA, and phase separate due to long-range charge effects and short-range hydrophobic effects. While evolution has optimized the self-assembly of these types of biological polymers, our ability to design such materials remains limited, in part because the relevant …

Kinetics Of The Crystal-Melt Phase Transformation In Semicrystalline Polymers, Kiran Subramaniam Iyer

Doctoral Dissertations

The assembly of long-chain polymers into an ordered state is a process that has puzzled polymer scientists for several decades. A process that is largely controlled by the strength of intermolecular attractions in small molecular systems, this crystallization in the case of polymers is controlled by a competition between the aforementioned force of attraction between monomers and the formidable conformational entropy of polymer chains. Any factor that affects this conformational entropy, whether that is an equilibrium thermodynamic factor or a kinetic factor, has the ability to control polymer crystallization. In this thesis, we focus on understanding the underlying kinetic processes …

What Difference Does A Catalyst Make?, Tammy Guthrie, Mike Jackson, Holly Haney

High School Lesson Plans

Students will use different catalysts for the decomposition of Hydrogen Peroxide, to determine if different catalysts affect the energy that is generated during the reaction.

A Study Of The Thermodynamics Of Small Systems And Phase Transition In Bulk Square Well-Hard Disk Binary Mixture, Gulce Kalyoncu

Graduate Theses and Dissertations

Under the umbrella of statistical mechanics and particle-based simulations, two distinct problems have been discussed in this study. The first part included systems of finite clusters of three and 13 particles, where the particles are interacting via Lennard Jones potential. A machine learning technique, Diffusion Maps (DMap), has been employed to the large datasets of thermodynamically small systems from Monte Carlo simulations in order to identify the structural and energetic changes in these systems. DMap suggests at most three dimensions are required to describe and identify the systems with 9 (N = 3) and 39 (N = 13) dimensions. At …

Nonlinear Dimensionality Reduction For The Thermodynamics Of Small Clusters Of Particles, Aditya Dendukuri

Graduate Theses and Dissertations

This work employs tools and methods from computer science to study clusters comprising a small number N of interacting particles, which are of interest in science, engineering, and nanotechnology. Specifically, the thermodynamics of such clusters is studied using techniques from spectral graph theory (SGT) and machine learning (ML). SGT is used to define the structure of the clusters and ML is used on ensembles of cluster configurations to detect state variables that can be used to model the thermodynamic properties of the system. While the most fundamental description of a cluster is in 3N dimensions, i.e., the Cartesian coordinates of …

Semi-Lagrangian Implicit Bhatnagar-Gross-Krook Collision Model For The Finite-Volume Discrete Boltzmann Method, Leitao Chen, Sauro Succi, Xiaofeng Cai, Laura Schaefer

Publications

In order to increase the accuracy of temporal solutions, reduce the computational cost of time marching, and improve the stability associated with collisions for the finite-volume discrete Boltzmann method, an advanced implicit Bhatnagar-Gross-Krook (BGK) collision model using a semi-Lagrangian approach is proposed in this paper. Unlike existing models, in which the implicit BGK collision is resolved either by a temporal extrapolation or by a variable transformation, the proposed model removes the implicitness by tracing the particle distribution functions (PDFs) back in time along their characteristic paths during the collision process. An interpolation scheme is needed to evaluate the PDFs at …

Comparative Analysis Of Simulation Models Of The Production Of Ethylbenzene, Osariemen Imafidon

Honors Theses

Process Engineering is all about making sure a raw material can become the desired product with as little variation as possible, while achieving the customer's specifications. Many equipment used for chemical processes cannot be physically inspected during operation at steady state, hence, the need for simulation software. The objective of this study was to compare the results of three different simulation packages to evaluate their efficacy within process design.

This study focused on the economic analysis of the production of Ethylbenzene using various models. The base case variables were inputted into each model to simulate the calculations for a fully …

Improving Pv Module Efficiency Through Cooling, Blake Bradley

Chemical Engineering Undergraduate Honors Theses

The Solarbacks researched and designed a variety of cooling methods that could be used to improve the efficiency of photovoltaics. These cooling methods can be separated into two categories: active and passive methods. The active cooling method of hydraulic cooling and the passive cooling methods of heat sinks (fins), optical coatings, thermosyphons, phase change materials, and thermoelectric generators were all taken into consideration as potential cooling methods. Passive cooling methods were preferred because the use of electricity required for the cooling mechanism would reduce the net electricity and subsequent profit from the panels.

Two variations of hydraulic cooling were researched: …

Improving Pv Module Efficiency Through Cooling, Brandon Conrad, Blake Bradley, Ashley Cox, Donhy Mai, Harrison Dawson, Megan Reynolds, George Hill

Chemical Engineering Undergraduate Honors Theses

The Solarbacks researched and designed a variety of cooling methods that could be used to improve the efficiency of photovoltaics. These cooling methods can be separated into two categories: active and passive methods. The active cooling method of hydraulic cooling and the passive cooling methods of heat sinks (fins), optical coatings, thermosyphons, phase change materials, and thermoelectric generators were all taken into consideration as potential cooling methods. Passive cooling methods were preferred because the use of electricity required for the cooling mechanism would reduce the net electricity and subsequent profit from the panels.

Two variations of hydraulic cooling were researched: …

Solution To Exide Technologies Inbatec Inefficiency, Mary Fairley, Reagan Gilker, Spencer Christian, Shixuan Hou, Covenson Latouche

Chemical Engineering Undergraduate Honors Theses

The inefficiency of the battery charging time in Inbatec Units 1 and 2 in the Exide Technologies Fort Smith was initially investigated by a student team in Fall 2019, and the investigation was continued into Spring 2020. The Exide Technologies facility in Fort Smith, Arkansas utilizes 13 Inbatec units to charge the lead-acid batteries.

The Inbatec systems circulate the sulfuric acid solution through a cooling tower to maintain to optimal charging temperature. Previous analysis of the charging process for Inbatec Units 1 and 2 show the cooling tower have the capacity to quickly remove the excess heat in the sulfuric …

Solution To Exide Technologies Inbatec Inefficiency, Shixuan Hou, Reagan Gilker, Mary Fairley, Spencer Christian, Covenson Latouche

Chemical Engineering Undergraduate Honors Theses

The inefficiency of the battery charging time in Inbatec Units 1 and 2 in the Exide Technologies Fort Smith was initially investigated by a student team in Fall 2019, and the investigation was continued into Spring 2020. The Exide Technologies facility in Fort Smith, Arkansas utilizes 13 Inbatec units to charge the lead-acid batteries. The Inbatec systems circulate the sulfuric acid solution through a cooling tower to maintain to optimal charging temperature. Previous analysis of the charging process for Inbatec Units 1 and 2 show the cooling tower have the capacity to quickly remove the excess heat in the sulfuric …

Solution To Exide Technologies Inbatec Inefficiency, Spencer Christian, Shixuan Hou, Mary Fairley, Reagan Gilker, Covenson Latouche

Chemical Engineering Undergraduate Honors Theses

The inefficiency of the battery charging time in Inbatec Units 1 and 2 in the Exide Technologies Fort Smith was initially investigated by a student team in Fall 2019, and the investigation was continued into Spring 2020. The Exide Technologies facility in Fort Smith, Arkansas utilizes 13 Inbatec units to charge the lead-acid batteries. The Inbatec systems circulate the sulfuric acid solution through a cooling tower to maintain to optimal charging temperature. Previous analysis of the charging process for Inbatec Units 1 and 2 show the cooling tower have the capacity to quickly remove the excess heat in the sulfuric …

Numerical And Experimental Analysis Of Air-Cooled Condensers, Kaipo Kekaula

UNLV Theses, Dissertations, Professional Papers, and Capstones

The scope of this project is to numerically and experimentally dry cooling process in air-cooled condensers (ACCs) designed for concentrated solar power (CSP) applications. This effort is driven by the growing economic and political pressure to reduce water consumption during power generation due to limited water resources in the arid geographic climate of the southwestern United States. A computational approach is used in conjunction with experimental validation to gain a more complete understanding of these systems.

Traditionally research into ACCs have been largely limited to air-side heat transfer modelling as it accounts for a large portion of the total thermal …

The Effect Of Oxygen On Properties Of Zirconium Metal, Jie Zhao

Doctoral Dissertations

The influence of oxygen on the thermophysical properties of zirconium has been investigated using MSL-EML (Material Science Laboratory Electromagnetic Levitator) on ISS (International Space Station) in collaboration with NASA (National Aeronautics and Space Administration), ESA (European Space Agency), and DLR (German Aerospace Center). Zirconium samples with different oxygen concentrations was subjected to multiple melt cycles during which the thermophysical properties, such as density, viscosity and surface tension, have been measured at various undercooled and superheated temperatures. Also, there are melt cycles for verifying the solidification mechanism. Similar samples were found to show anomalous nucleation of the solid for certain ranges …

Rational Interface Design For High-Performance All-Solid-State Lithium Batteries, Changhong Wang

Electronic Thesis and Dissertation Repository

All-solid-state lithium batteries (ASSLBs) have gained substantial attention owing to their excellent safety and high energy density. However, the development of ASSLBs has been hindered by large interfacial resistance originating from the detrimental interfacial reactions, poor solid-solid contact, and lithium dendrite growth. The research in this thesis aims at achieving high-performance ASSLBs via rational interface design and understanding the interfacial reaction mechanisms.

At the cathode interface, an ideal dual core-shell nanostructure was first designed. Moreover, single-crystal LiNi_0.5Mn_0.3Co_0.2O₂ (SC-NMC532) cathode was compared with polycrystalline NMC532, the former exhibits much enhanced Li⁺ diffusion kinetics …

Desarrollo De Un Esquema De Gestión Hídrica En El Sistema Acuífero Sap 3.1 Apoyado De La Tipificación De Suelos Y El Modelo Conceptual De Thöt, Maria Camila Soriano Espinosa, Camilo José Rodríguez Carvajal

Ingeniería Ambiental y Sanitaria

El presente proyecto tiene como objetivo principal desarrollar un esquema de gestión hídrica (EGH) en el sistema acuífero SAP 3.1, provincia llanos orientales, con base en la tipificación de suelos y el modelo conceptual de Tӧth, partiendo de que las aguas subterráneas se consideran una fuente alternativa de abastecimiento por su mejor calidad y el bajo costo de manejo en comparación al agua superficial, y teniendo en cuenta que el Departamento del Meta conoce la riqueza hídrica que está en su jurisdicción, no cuenta con una regulación adecuada en pro de una gestión hídrica a nivel subterráneo. La metodología empleada …

Experimental And Computational Characterization Of Sodium Nitrate @ Silica Nano Capsules For Thermal Energy Storage Applications, Wataru Hashimoto

Graduate Research Theses & Dissertations

In this investigation, a nanocapsule composed of a sodium nitrate core and a silicon dioxide shell is synthesized, characterized, and analyzed utilizing a mixture of analytical and computational tools. The sol-gel method was selected as the process of nanoencapsulation. Analytical characterization techniques employed in this investigation include differential scanning calorimetry (DSC) to measure melting temperatures and enthalpies of fusion, dynamic light scattering (DLS) to calculate particle size distributions, scanning electron microscopy (SEM) to analyze surface characteristics, transmission electron microscopy (TEM) to perform shell characterization, and energy dispersive X-ray spectroscopy (EDS) to determine chemical composition. Preliminary results indicated a decrease in …

Process Development Of Shale Gas Assisted Lignin And Biomass Reforming Through Novel Reaction Pathway And Catalyst Design To Produce Hydrogen Rich Syngas For Fuels And Value Added Chemicals, Amoolya D. Lalsare

Graduate Theses, Dissertations, and Problem Reports

Novel biomass reforming strategy through synergistic co-processing with flare gas (methane and carbon dioxide) was developed at West Virginia University. Hardwood biomass comprised of lignin, hemicellulose, and cellulose is abundant in the US and potentially a sustainable source of hydrogen through extensive reforming and gasification. Ever-increasing shale gas production in the US occasionally leads to flaring owing to stranded production across the US. Achieving biomass co-processing with natural gas about to be flared in such stranded shale plays is the underlying motivation here. A novel reaction pathway was discovered wherein methane and carbon dioxide assisted reforming of biomass could be …

Process Modeling And Techno-Economic Analysis Of Thermo-Catalytic Dimethyl Ether Synthesis And Microwave-Based Aromatics Production Technologies From Shale Gas, Chirag Mevawala

Graduate Theses, Dissertations, and Problem Reports

Production of dimethyl ether (DME) and direct non-oxidative methane dehydroaromatization (DHA) to aromatics via conventional and microwave (MW)-assisted processes are investigated in this research. Plant-wide models of the shale gas to DME process with integrated CO₂ capture via direct and indirect synthesis routes have been developed. Optimal parameter estimation, and model validation are undertaken for various sections of the process including the pre-reforming reactor, auto-thermal reforming reactor, DME synthesis reactors, CO₂ capture units and separation sections. A novel DME separation process has been developed for efficient separation of DME, syngas, and CO₂. Plant-wide techno-economic optimization is …

Thermal / Structural Analysis Of The Hb 650 Thermal Shield, Gerald J. Smith

Graduate Research Theses & Dissertations

Fermilab’s PIP-II project’s superconducting linear accelerator (Linac) will drive the next generation of particle accelerators through a revolution in beam intensity. Key to beam intensification are the high efficiencies of niobium-tin superconducting radiofrequency (SRF) cavities operating at cryogenic temperatures near 5 Kelvin. A multifaceted approach is employed to achieve and maintain the extreme temperature. Vacuum provides the first barrier to thermal convection. Physical thermal intercept zones further isolate the exterior shell vacuum vessel at 300 Kelvin from the supercooled beamline. The first thermal intercept lies just inside the exterior vacuum vessel forming the 40 Kelvin zone. This 40K thermal shield …

Coarse-Grained Dynamically Accurate Simulations Of Ionic Liquids At Vacuum-Interface, Tyler D. Stoffel

Theses and Dissertations--Mechanical Engineering

Ionic liquids, possessing improved properties in many areas of technical application, are excellent candidates as components in development of next-generation technology, including ultra-high energy batteries. If they are thus applied, however, extensive interfacial analysis of any selected ionic configuration will likely be required. Molecular dynamics (MD) provides an advantageous route by which this may be accomplished, but can fall short in observing some phenomena only present at larger time/length scales than it can simulate. Often times this is approached by coarse-graining (CG), with which scope of simulation can be significantly increased. However, coarse-grained MD systems are generally known to produce …

Investigation Of Asphaltene Adsorption At Liquid-Liquid And Liquid-Solid Interfaces, Fang Liu

Dissertations and Theses

Asphaltenes, as indigenous components in crude oils, are believed to play an important role in the petroleum production and processing industry. For example, asphaltene molecules can adsorb onto the water / oil interface like the amphiphiles and hinder water droplet coalescence, resulting in the stabilization of water-in-oil emulsions. Also, in the upstream production, depending on the temperature and pressure, asphaltenes can precipitate and deposit onto the reservoir rocks, the wellbores and the pipelines, leading to the change in reservoir rocks’ surface wettability and the blockage of the production facilities. Hence, it is crucial to understand the mechanism of asphaltenes adsorption …